1. Field of the Invention
The present invention relates to an image processing apparatus and a method of controlling the apparatus.
2. Description of the Related Art
Editing still images uses Raw development processing which can obtain images corresponding to development parameters when the user designates various development parameters for image data in Raw format obtained by recording the image signals generated by an image capturing device. Note that development parameters are pieces of information necessary to adjust an image (its image quality), for example, the contrast, exposure correction, white balance, and hue.
In addition, recently, with the popularization of digital video cameras and improvement in the performance of personal computers, it has become a general practice to edit also moving images. Under the circumstances, image data in Raw format have been handled for moving images as well as still images. That is, it is thought that digital video cameras capable of recording files in Raw format will be in widespread use.
Unlike still image data, moving image data includes the image data of many frames (image frames). In order to properly express moving image data in Raw format (Raw moving image data), it is necessary to record (add) development parameters in all the Raw image frames constituting the Raw moving image data in advance. However, in one moving image content, development parameters hardly change greatly on a frame basis especially in the same scene, and hence it is not efficient to record development parameters for all the Raw image frames constituting the moving image content.
For this reason, Japanese Patent Laid-Open No. 2009-55335 has proposed a technique of recording development parameters for only Raw image frames at predetermined intervals when recording Raw moving image data. The technique disclosed in Japanese Patent Laid-Open No. 2009-55335 generates development parameters for Raw image frames, for which no development parameters have been recorded, by performing interpolation processing using the development parameters of Raw image frames at predetermined intervals when reproducing (developing) Raw moving image data.
According to the prior art, however, since development parameters are recorded for only Raw image frames at predetermined intervals, a development parameter is not always recorded for a Raw image frame corresponding to a scene felt important by the user (to be referred to as a “scene of interest” hereinafter).
FIG. 6 is a view showing Raw moving image data to be recorded in the prior art, in which Raw image frames constituting Raw moving image data and development parameters (color temperatures) are arranged along the time axis. An apparatus such as a digital video camera to record Raw moving image data generally performs development processing for image data to display an object on an electronic view finder (EVF). As shown in FIG. 6, therefore, the apparatus records color temperatures P1 and Pm, as one type of development parameters, generated in development processing at the time of EVF display, respectively, for Raw image frames F1 and Fm, appearing at predetermined intervals. Note that the apparatus has generated development parameters for all the Raw image frames constituting Raw moving image data, and has also generated a color temperature Ps for a Raw image frame Fn between the Raw image frames F1 and Fm appearing at the predetermined intervals, at the time of EVF display. In the prior art, however, since development parameters are recorded for only the Raw image frames F1 and Fm appearing at the predetermined intervals, the color temperature Ps is not recorded for the Raw image frame Fn.
When reproducing Raw moving image data, the apparatus generates a color temperature Pn as a color temperature for the Raw image frame Fn by interpolation processing using the color temperatures P1 and Pm. However, the color temperature Pn is different from the actual color temperature Ps. Even if, therefore, the Raw image frame Fn corresponds to a scene of interest, the Raw image frame Fn is developed with the color temperature Pn different from the actual color temperature Ps (the color temperature assumed by the user at the time of image capturing). In order to develop the Raw image frame Fn with the actual color temperature, the user needs to perform development again by adjusting the development parameter generated by interpolation processing (that is, it takes much labor and time to obtain a target image).